FAQ
TL;DR: US→EU conversion means units, radio step change (200→100), and lighting—"The lights need to be coded." Use SD C4/DAS workflows below. [Elektroda, viper1989, post #17038666]
Why it matters: This FAQ helps technicians convert US‑spec Mercedes to EU settings safely and efficiently with SD C4/Xentry/Vediamo.
Quick Facts
- Online coding via Xentry is recommended for reliable parameter changes. [Elektroda, Eidems, post #17040250]
- Some options require SD Developer rights; others need Vediamo access. [Elektroda, damdam, post #17045730]
- To persist coding, exit with F2/F3 and confirm “transfer new coding to this module.” [Elektroda, viper1989, post #17538272]
- F°→C° and mi→km live in the KI/KIW cluster; use “Rest of World” if values conflict. [Elektroda, viper1989, post #17496039]
- US FM step differs from EU (200 vs 100); region recode resolves tuning steps. [Elektroda, viper1989, post #17038666]
How do I change Fahrenheit to Celsius and miles to kilometers with SD C4?
Use DAS/Xentry module coding, then confirm the write. 1. Enter the relevant control module’s coding. 2. Change units to Celsius and kilometers. 3. Press F2, then F3; confirm the prompt to transfer coding to the module. [Elektroda, viper1989, post #17538272]
Where do I find the units setting (KI/KIW), and how do I confirm changes?
Open DAS, go to the KI/KIW (instrument cluster) coding. Change F°→C° and mi→km. Press F2, then F3, and accept the “coding changed” confirmation dialog to save it. If conflicts appear, set region to “Rest of World.” [Elektroda, viper1989, post #17496039]
My changes revert after cycling the ignition—what did I miss?
You coded values but didn’t transfer them to the module. Exit with F2/F3 and accept the prompt to write new coding. If you key off without that, settings revert. [Elektroda, viper1989, post #17538272]
Can I do this offline, or do I need Xentry online coding?
Use online coding for dependable results. “Buy access to Xentry and do online coding.” Offline methods can be limited or blocked by datasets. [Elektroda, Eidems, post #17040250]
Do I need Developer rights or Vediamo for US→EU conversion?
Yes. Some parameters are accessible only with SD Developer rights, and others require Vediamo for deeper variant coding. Plan tool access accordingly. [Elektroda, damdam, post #17045730]
What are the US vs EU FM tuning steps on these cars?
The forum case notes US radios stepping by 200 and EU by 100. After recoding market/region, the tuner aligns with EU steps. [Elektroda, viper1989, post #17038666]
How do I switch the radio from US to EU region?
Code the market/region to EU or “Rest of World” in relevant modules, then confirm the transfer on exit (F2/F3). This aligns radio behavior. [Elektroda, viper1989, post #17496039]
Can I recode US LED lights to EU spec, or do I need to replace them?
Coding alone may not solve US lighting differences. “This used to be called headlight replacement.” Expect issues with turn signals integrated with STOP lights and red lenses on US-spec cars. [Elektroda, jdubowski, post #17038710]
Which Mercedes models are in scope here?
The thread addresses an S‑Class Coupe W217 and GLS X166 for unit and region conversions (F→C and miles→km). [Elektroda, viper1989, post #17106969]
How long does a US→EU coding session take?
Plan around one hour, depending on the number of modules you must touch. That timing was reported for on-site coding. [Elektroda, viper1989, post #17040016]
I can’t find “Construction/Design Data” for KI/KIW—what’s the workaround?
Use “modify module” coding rather than “Design Data.” After changes, exit with F2/F3 and accept the transfer prompt so values persist. [Elektroda, viper1989, post #17538272]
Do I need a battery support or power supply during coding?
Yes. Use a battery support/rectifier to hold stable voltage during coding or flashing. Typical target is ~13.5–14.5 V with sufficient current to avoid resets. This prevents aborted writes and module faults. [Mercedes-Benz, 2017]
What SD/Xentry version worked here, and any DAS vs Xentry limitation?
A 09.2017 SD C4 setup was used. Note that DAS may list fewer vehicles than Xentry in the same install. [Elektroda, viper1989, post #17594717]
Is there a walkthrough for changing temperature units to Celsius?
Yes. See the referenced OBDII365 blog category for MB Star tips, including Fahrenheit→Celsius changes with SD tooling. [Elektroda, citromaniak, post #17040558]
